Supercooling means that a liquid such as water is not transited to a solid but maintained in a high temperature phase, namely, a liquid phase even below a phase transition temperature to the solid. Water drops can be supercooled in the natural state. In addition, water or beverages may be incidentally supercooled in a general refrigerator. A freezing method disclosed under Japan Laid-Open Patent Official Gazette S59-151834 and a freezing method and a refrigerator disclosed under Japan Laid-Open Patent Official Gazette 2001-086967 apply the supercooling principle to the refrigerator. An electric field or a magnetic field is applied to foods of the refrigerator, so that the foods can be maintained in a supercooled state below a phase transition temperature. An electrostatic field processing method disclosed under International Publication Official Gazette WO/98/41115 suggests various types of electrode structures that can be used to supercool and thaw foods.
FIG. 1 is a structure view illustrating a conventional refrigerator including a dispenser. The refrigerator 300 includes a freezing chamber 310 and a refrigerating chamber 320. An ice maker 330 is installed in the freezing chamber 310, and the dispenser 350 is installed on the freezing chamber door 340. A passage 360 is formed to supply water to the ice maker 330 and the dispenser 350, and connected to an external water supply source (not shown). A first valve 370, a filter 380 and a second valve 390 are disposed on the passage 360. The first valve 370 controls water supply from the external water supply source to the refrigerator 300, the filter 380 filters water, and the second valve 390 controls water supply to the ice maker 330 and the dispenser 350.
On the other hand, the first valve 370 and the second vale 390 are controlled by a control unit (not shown) of the refrigerator 300. The passage 360 includes a passage 361 for supplying water to the dispenser 350. Water flowing through the passage 361 is cooled by heat exchange with the freezing chamber 310, and discharged through an outlet 362 of the passage 361 or an outlet 351 of the dispenser 350.
FIG. 2 is a structure view illustrating a transparent ice maker disclosed under Korea Laid-Open Patent Official Gazette 2006-0013721. The transparent ice maker 100 includes a supercooling means 120 using blades 122. Thin plate ice is laminated by supplying supercooled water made by the supercooling means 120 to an ice making means 110 including an ice tray 111, an ice making chamber 112 and ejectors 113 at very small quantities, thereby malting transparent ice.
FIGS. 3 and 4 are structure views illustrating a microwave oven for generating microwaves disclosed under Korea Laid-Open Patent Official Gazette 2005-0002271. The microwave oven includes a door 400 and a main body 120. The door 400 has latches 510 and 520. The main body 120 has switches 710, 720 and 730. By this configuration, when the door 400 is opened, generation of microwaves is intercepted by a mechanical method without the help of a control unit.
The conventional refrigerator of FIG. 1 does not provide a supercooled liquid. The conventional transparent ice maker of FIG. 2 supercools water by the mechanical method using the blades, and makes the thin plate ice by supplying the supercooled water at very small quantities. Therefore, the conventional transparent ice maker cannot rapidly make slush or ice. In the case that the supercooled water is transited to a solid phase and frozen, the conventional art cannot solve the problem.
In the general refrigerator, when foods are kept in the storing chamber in the supercooled state, they are often frozen.